Human embryonic stem cells are cloned

12:54 PM,
May 15, 2013

The first step during cloning is removal of chromosome genetic material from a human egg. A hole is made in the egg's shell and a pipette (on the right) slowly remove the chromosomes from the center of the egg.

Written by

Dan Vergano
USA TODAY

An international research team has achieved a scientific first by producing embryonic stem cells from cloned embryos, advancing the effort to generate replacement tissues for sick patients.

Embryonic stems cells are the starter cells to all others in the body, which means potentially they can grow into any type of tissue, from blood to bone to brain. For a decade-and-a-half, they have been seen as a potential source of rejection-free transplant tissues for ailments ranging from diabetes to paralysis. They were also the subject of a fierce political fight over the medical ethics of using ...